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Y UNITED STATES ATENT OFFICE.

GEORGE IV. SCOLLAY, OF NEV YORK, N. Y.

PROCESS OF REFINING COTTON-SEED OIL.

SPECIFICATION forming part of Letters Patent No. 405,852, dated June 25, 1889.

Application filed January 12, 1889. Serial No. 296,170. (No specimens.)

To all whom it may concern.-

Be it known that I, GEORGE W. SCOLLAY, a citizen ot the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Refining Cotton-Seed Oil, of which the following is a description in such full, clear, and concise terms as will enable any one skilled in the art to which my invention appertains to make and use the same.

The ordinary method of refining crude cotton-seed and other analogous oils into the yellow oil of commerce is to treat said oil while raised to a temperature from, say, about 100 to 125 Fahrenheit with a caustic-soda lye or eaustic-potassa lye of 'arying specific gravities, indicated by the hydrometer. The percentage of solution required varies from three to eight per cent, according to the character of the oil and the strength of the solution; but it is used in quantities sufficient to remove the impurities therefrom and to bring it to a bright yellow color. During this treatment not only are the impurities removed, but a considerable quantity of the oil is decomposed and the acids saponified.

The object of my present invention is to effect a saving of the oil, or, in other words, to obtain from a given quality and quantity of crude oil a larger quantity of yellow oil, commonly called the oil of commerce. The oil refined according to the process herein described will also be of a superior quality, and hence more valuable.

I have discovered in my investigation and experiments that by a suitable alkalisuch, for example, as caustic-soda lye or causticpotassa lyeto treat and but partially refine crude cotton-seed oil, and by then completing the refining by suitable ochers a saving of from one to four gallons of oil per barrel will be effected, which by the old process is lost by being made into soap. Besides, the oil will be of much better flavor and of a uniform yellow color. This is particularly the case with that class of oils known as offoils.

In the practice of my invention I have employed, where it would require four per cent. of caustic-soda lye or caustic-potassa lye to completely refine the oil, from two to three per cent, and where it would require six per cent. to completely refine the oil from three to four and one-half per cent, and where it would require eight per cent. to completely refine the oil I have used from four to five and one-half per cent, the solution and oil being the same.

The following is a description of my improved method of refining crude cotton-seed oil in the form in which I now prefer to practice it: Take one hundred barrels of .erude cotton-seed oil and place it in a suitable tank, where the temperature of the oil is raised, say, to 80 Fahrenheit. Alkali such as caustic-soda lye or eaustic-potassa lyeis then added in quantities sufficient to only partially refine the oil. The quantity of alkali employed, as well as its specific gravity, depends upon the character of the oil; but the amount I have used is from about one-half to one-eighth less than is necessary to completely refine the oil as standard yellow cotton-seed oil of commerce. I then agitate the oil for from, say, thirty to sixty minutes and with a rising temperature allow separation and settling of the impurities to take place. The oil is now but partially refined and is 'still of a dull red color; but the grosser impurities have been largely eliminated from it and the free fatty acids saponified. The less gross impurities still remain,but little oil has been decomposed and saponified, The less gross impurities consist, to a con siderable degree, in coloring-matter, and could be removed and the refiningprocess completed by continuing the treatment with alkali, and this is the process which is now practiced; but if alkali be used to complete the refining a considerable quantity of the oil will be decomposed and saponified. To take out these less gross impurities without loss of oil,I have pumped, after it has settled, the partially-refined oil into another tank and have added to the oil from, say, two to five per cent. of a suitably-prepared ocher, (dried, it necessary,) according to the character of the oil. I then agitate it from, say, fifteen to thirty minutes, with the oil at a temperature of from, say, 120 to 135 Fahrenheit, when the refining will be complete. It may now be passed through a suitable filter-press, after which it is ready for the market.

An examination of the oil refined by this process shows that less oil has been saponified, and that the bouquet or nutty flavor of the oil is more fully retained.

The grosser impurities of crude oil cannot be so easily or economically taken out by ocher alone, as a very large quantity of ocher would have to be employed and a large quan-' tity of the oil would be absorbed by and would remain with the ocher. These grosser impurities, with the free fatty acids, are readily attacked and removed by suitable alkali and with a minimum loss of oil. With the less gross impurities the reverse is true. To remove them by alkali involves the loss of considerable oil, Whereas they readily yield to treatment with ocher, and but a comparatively small amount of oil is absorbed by the ocher.

Fullers-earth may be employed as a substitute for ocher in the practice of my invention; but when used no valuable product results, and the earth and from ten to fifteen per cent. of its weight in oil is lost, whereas when ocher is used it is converted into paint or paint-stock with no loss of oil or ocher, as has been pointed out in Patents Nos. 378,113, 37 7,406, and 37 3,114, previously granted to me. For this reason I prefer to employ ocher in completing the refining process, although my invention is not limited to its use, but includes as equivalents such materials as fullers-earth.

I am aware that it is not new to treat crude cotton-seed oil with a quantity of alkali sufficient to refine it into the yellow oil of commerce, and subsequently to treat this yellow oil with fullers-earth to make white oil. My process differs from this in stopping the treatment of the oil with alkali before it has reached yellow oil, and when the grosser impurities have been separated from it and before the less gross impurities have been removed, and then treating said partially-re fined oil with a suitable substancesuch as ocher or fullers-earth-to remove the less gross impurities and to complete the refining process to make the ordinary yellow oil of commerce. Of course more ocher or fullersearth may be added, all the color removed, and white oil be produced.

In conclusion I desire to remark that the temperatures-above indicated and the periods of time thatthe oil is agitated in the steps of my process are recited merely as examples of how the method may be practically employed,- the cardinal feature of the invention whichl desire to secure by these Letters Patent being the treatment of the crude oil at any suitable temperature and for a suitable length of time with alkali until it is only partially brought to the condition known as yellow oil, and subsequently treating it under suitable conditions with such -a substance as ocher or fullers-earth to complete the refining process.

Having thus described the manner in which I prefer to carry on my invention, what I claim, and desire to secure by these Letters Patent, is

In the manufacture of refined cotton-seed and other analogous oils, the process, substan-- tially as described, of treating crude oil with suitable alkalisuch as caustic-soda lye'or caustic-'potassa lye-euntil the grosser impurities are removed and the oil only partially 7 brought to the condition of yellow oil of commerce, and of subsequently treating said partially-refined oil with ocher or fullers-earth to complete the refining.

GEO. W'. SCOLLAY. WVitnesses:

J. EDGAR BULL, R. A. CoRINALnI. 

